The determination of how-to treat a highly ill patient can be very difficult, especially under the chaotic and emotional conditions that may exist in the conditions surrounding around such a highly ill patient. For example, such an ill patient may be treated in the context of an emergency situation such as shock, high risk surgery, trauma and other acute conditions requiring emergency treatment. It has been found by the inventors that diagnosis errors commonly occur under those emergency conditions.
It is also difficult, especially in these emergency situations, to evaluate the timing of a given therapy. A given therapy that improves the outcome at one point may actual produce harm at a different point, or when used in the wrong amount for the wrong situation. For example, fluid therapy used at the initial phase of resuscitation may be critical. However, use of excess fluids may lead to pulmonary edema and cardiac failure. Such errors can be lethal in emergency situations. Moreover, many different injuries, shock being one, may be easy to recognize in late stage when therapy is often ineffective. If hypovolemia is inferred from tachycardia, hypotension, and falling hematocrit, these superficial manifestations of shock may be overtly corrected by transfusions, fluids, and vasopressors, but still without adequately restoring the underlying circulatory functions.
It has been found that effective resuscitation of acute life-threatening emergencies achieves optimal physiological goals as early as possible. When circulatory mechanisms are identified earlier and treated more vigorously to specified physiologic target goals, outcomes are improved.
The incidence, mortality, morbidity, and costs of life threatening illnesses and injuries are extraordinary. Among the 1.9 million deaths annually, about half are from acute illness associated with shock and lethal organ failure. There are over 34 million surgical-operations annually in the U.S., with an overall mortality of 1%, but high-risk surgical patients have mortality between 25 and 33%. Postoperative deaths are often due to adult respiratory distress syndrome (ARDS), which has an incidence of 150,000, a mortality of around 40%, consumes an average of two weeks in the ICU, and in this country costs about $1,950,000,000 annually. There are about one-half million septic patients, of whom 40% develop shock, with 50% mortality. Septic shock is the 13th leading cause of death, and the most common cause of ICU deaths. Hospital costs for septic shock are over 5 billion dollars annually.
Conventionally, shock is classified as hemorrhagic, traumatic, postoperative, neurogenic, and distributive or septic. Usually this classification is applied to the later, fully developed, clinical syndromes of shock. Analysis of circulatory mechanisms when patients are admitted to the ICU in the late stage, after organ failure has occurred, is extremely complex because of the many interacting clinical, physiological, and immunochemical problems. Over 12 separate cascades of chemical mechanisms have been described. Many of these have been considered to be the cause of shock, and major efforts have been expended to reverse them. Of the 11 or more large scale, multicenter, randomized clinical trials, only the recombinant human activated protein C (drotrecogin alfa activated) has shown improvement in mortality, which decreased from 30.8% in the placebo control group to 24.7% in the protocol group, a decrease of 6.1% (38). The many interacting immunochemical mechanisms make the problems of sorting out causal relationships more difficult, and the therapy less effective, after organ failure and sepsis have become established in the late stages of critical illness.
There are six commonly used outcome predictors: the Acute Physiology and Chronic Health Evaluation (APACHE), Glasgow Coma Scale (GCS), the penetrating abdominal injury (PATI) score, the Therapeutic Intervention Scoring System (TISS), The Revised Trauma Score and Injury Severity Score (TRISS) and the Trauma score. All of them assess categories of patients in terms of probable mortality. The are not intended to predict mortality risk for a specific single patient. Those systems are rarely used for guiding actual patient care. They find their greatest use as a tool for administrative and management research and decisions. Longitudinal scoring on successive days may reflect continuous improvement, but has no physiologic or therapeutic relevance for any specific individual patient. Moreover, none of them identify specific underlying physiologic mechanisms or problems as does the present approach. In addition, none of them considers specific therapeutic recommendations to be suggested, real-time, to the physician. Finally, none are able to recommend titration of therapy to alleviate the underlying hemodynamic problem or to achieve optimal goals.